As one of California’s most invaluable natural resources, the Delta has been stretched to the breaking point. Its ecosystem is in steep decline, which jeopardizes the Delta’s ability to provide water supplies and support fisheries.
Over the last 150 years, the Delta has been altered by a system of manmade levees, reservoirs, and dredged waterways constructed to support farming and urban development and to provide flood protection for local towns and cities. The natural flows in the Delta also can be altered by operation of the State Water Project (SWP) and Central Valley Project (CVP), which deliver water to millions of Californians. Many other factors affect species health in the Delta, including water quality issues, nonnative species, illegal fishing, and smaller, local water diversions. The Delta is also threatened by continuing land subsidence, seismic risk, and effects of climate change.
In this highly altered environment, several fish species have declined to the lowest population numbers in their recorded histories. To address this decline in fish population, federal regulators have placed limits on Delta water deliveries.
While environmental restrictions on water deliveries are meant to protect Delta fish species, they also reduce the operational flexibility of the SWP and CVP needed to meet statewide water supply needs. The existing water delivery infrastructure is also aging and inefficient, further reducing water supply reliability. Without changes to the way water currently flows through the Delta, Californians risk:
- A loss of secure and reliable drinking water supplies for millions of people
- Damage to the statewide economy, loss of jobs and loss of business
- Further degradation of precious natural resources and extinction of native species
Current conditions in the Delta are unsustainable, and action is needed to invest in infrastructure improvements necessary to protect critical habitat and secure reliable water supplies.
The Current State of the Delta
Over time, the Delta has been altered by a system of manmade levees, reservoirs, and dredged waterways. Changes to the Delta ecosystem have affected species health and limited the reliability of statewide water supplies.